ECMlink What causes noisy airflow in the upper RPM band to redline?

[Justin DuBois]

What causes noisy airflow in the upper RPM?

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[ist dwa]

Post a log...... for the 1millionth time.

 

[Justin DuBois]

Post a log...... for the 1millionth time.

Million and one

 

[DSMPT]

Could be wrong but first thing came up to mind is maybe you have the boost pressure unstable and zigzagging at high RPM. Should try different WG control parameters.

 

[Justin DuBois]

Could be wrong but first thing came up to mind is maybe you have the boost pressure unstable and zigzagging at high RPM. Should try different WG control parameters.

What change did you think might have an impact?

 

[DSMPT]

What change did you think might have an impact?

What happens if you bypass the boost controller solenoid and run only the wastegate spring pressure or lower the WG duty in the boost controller?

 

[ist dwa]

I've seen this before and it can be a marionette of things. Boost control is def one of the first, good wastegate, proper short line size and good controller. BOVs could be an issue. Also just the harmonics of the engine as well, length of intake/ exhaust etc. Try getting a way better tune first and see if it cleans up. Car is waaaay to rich at 10:1 (shoot for 11.5s on pump), your boost est and real boost are off 3psi which tells me your global is wrong and you have compensated greatly via the SD table which is in the 80s, at WOT regardless of Turbo size or boost you should always have VE between 92-98, if not your global is wrong.

 

[Justin DuBois]

I've seen this before and it can be a marionette of things. Boost control is def one of the first, good wastegate, proper short line size and good controller. BOVs could be an issue. Also just the harmonics of the engine as well, length of intake/ exhaust etc. Try getting a way better tune first and see if it cleans up. Car is waaaay to rich at 10:1 (shoot for 11.5s on pump), your boost est and real boost are off 3psi which tells me your global is wrong and you have compensated greatly via the SD table which is in the 80s, at WOT regardless of Turbo size or boost you should always have VE between 92-98, if not your global is wrong.

I've been working this setup for a while now - Big 16G - E25 (94oct) Fuel and 10:1 is a safe place to play until everything is calibrated. I'll work on different AFR targets in the DA tables after I'm satisfied with the calibration.

Here is a progression of setup changes - You could start all the way back before the fuel pump upgrade at the smog test:

https://www.dsmtuners.com/threads/itflys-1gina2g.532766/post-153899535

Or you can jump ahead to the last progression:
Final MAF setup before SD - SD table reset:

https://www.dsmtuners.com/threads/itflys-1gina2g.532766/post-153900920

Most relevant for this tune

https://www.dsmtuners.com/threads/itflys-1gina2g.532766/post-153901263

 

[ist dwa]

I'll say it one more time and then I am out. You are too rich, it has nothing to do with a safe space. That is an absurd A/F ratio, please lean it out, correct A/F can fix problems. Besides A/F are not nearly as dangerous as too much timing.

 

[Justin DuBois]

I'll say it one more time and then I am out. You are too rich, it has nothing to do with a safe space. That is an absurd A/F ratio, please lean it out, correct A/F can fix problems. Besides A/F are not nearly as dangerous as too much timing.

Alrighty, I’m ready to debate tuning approach - maybe you should post a log. Show me what you got.

 

[ist dwa]

I literally wrote the book on it.....

https://www.dsmtuners.com/threads/how-to-tune-a-1g-ecmlink-v3-using-speed-density.395564/

 

[DSMPT]

What change did you think might have an impact?

Can't tell if this is the direct cause of the issue, but this is what I thought first. Green line is your boost line, it is not smooth/stable and getting up/down approxi +/- 5 psi. Yellow is from my 2g with the same turbo and the boost range as yours, but mine stays within approxi 0.5 psi difference.

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[Justin DuBois]

I literally wrote the book on it.....

https://www.dsmtuners.com/threads/how-to-tune-a-1g-ecmlink-v3-using-speed-density.395564/

Nice work I like that reference - I'm interested in seeing what your timing table and DA targets look like.

 

[ist dwa]

Here is a 122MPH qt trap on a 14b on ethanol. This is of course changes with bigger turbos and more boost.

 

[Justin DuBois]

Can't tell if this is the direct cause of the issue, but this is what I thought first. Green line is your boost line, it is not smooth/stable and getting up/down approxi +/- 5 psi. Yellow is from my 2g with the same turbo and the boost range as yours, but mine stays within approxi 0.5 psi difference.

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Nice! that is what I want to fix for sure. I’ll try a run with the WG plumbed to a boost source, and bypass the Evo boost pill / 2G ECU WG boost control setup.

What boost sensor are you running, and where is it plumbed?

 

[DSMPT]

Nice! that is what I want to fix for sure. I’ll try a run with the WG plumbed to a boost source, and bypass the Evo boost pill / 2G ECU WG boost control setup.

What boost sensor are you running, and where is it plumbed?

I use a Greddy boost controller, the boost controller sensor is built-in. I have ECMLink in my 2g but I don't use it to control boost, mostly just for logging purpose. I even still use a 5 knob SAFC and ITC to tune my 2g

 

[Justin DuBois]

I use a Greddy boost controller, the boost controller sensor is built-in. I have ECMLink in my 2g but I don't use it to control boost, mostly just for logging purpose. I even still use a 5 knob SAFC and ITC to tune my 2g

My Profec-B was replaced by ECU-controlled which has been interesting. Not at all what I thought ECU controlled boost was going to be, but having a table of values per RPM is interesting.

What I meant was, where on the intake manifold are you getting a vac/boost source for the sensor?

 

[DSMPT]

My Profec-B was replaced by ECU-controlled which has been interesting. Not at all what I thought ECU controlled boost was going to be, but having a table of values per RPM is interesting.

What I meant was, where on the intake manifold are you getting a vac/boost source for the sensor?

For ECMLink, I have the MDP style Omni MAP sensor on 2g intake manifold MDP sensor port for now. For the boost controller, I am taking it from TB port. The port doesn't read vacuum when the throttle plate is closed, so it reads only boost, but I don't need my Profec boost controller to read vacuum so.

 

[Justin DuBois]

Here is a 122MPH qt trap on a 14b on ethanol. This is of course changes with bigger turbos and more boost.

Crazy go nuts on that timing table - Ethanol is easy that way (or hard depending on how you look at it).
And , max oct table? Yeah, I suppose if you target near stoic everywhere that's one less thing to deal with - How you figured this out - that's a better story to hear.

How about a 3rd gear pull? - what does your wide band and boost alignment with "est" look like?

 

[ist dwa]

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[Justin DuBois]

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Ah, I see. You're not trying to align AFRatioEst and WB.

 

[ist dwa]

Honestly it doesn't matter what your estimate is at, all you care about it what it is. Now changing the estimate will affect the A/F itself. But if the A/F is where you want it, that is all that matters. If you did change the A/F est to mimic it exactly in my case I would have to go in adjust the global to compensate to get it back to the A/F I want it to be. During a pull as long as it's mid11s-low13 that is fine by me, the line is usually not flat it moves around and some setups are flatter than others. The power is in timing you just need a copasetic A/F ratio.

The most important thing is real boost vs est boost because that calculates your airflow which does matter. If your boost est doesn't match then your airflow reading is either inflated or deflated depending how it goes. Higher boost est than real boost give high false reading of airflow and vice versa.

 

[Justin DuBois]

Honestly it doesn't matter what you estimate is at, all you care about it what it is. Now changing the estimate will affect the A/F itself. But if the A/F is where you want it, that is all that matters. If you did change the a/f est to mimic it exactly in my case I would have to go in adjust the global to compensate to get it back to the A/F I want it to be. During a pull as long as it's mid11s-low13 that is fine by me, the line is usually not flat it moves around and some setups are flater than others. The power is in timing you just need a copasetic A/F ratio.

The most important thing is real boost vs est boost because that calculates your airflow which does matter. If your boost est doesn't match then your airflow reading is either inflated or deflated depending how it goes. Higher boost est than real boost give high false reading of airflow and vice versa.

Interesting

When I was running 2G MAF with no adjustments to MAFcomp I was able to achieve very good AFRatioEst to Wideband alignment, in addition to BoostEst and GM3Bar alignment. Same setup I'm tuning now with SD. Same AFRatio targets, same E25 fuel.

The only difference is the VEtable and IAT inputs to replace the MAF input. It stands to reason that I should be able to achieve the same results in SD that I achieve with MAF.

That is what I'm trying to do anyway.

This instability in the airflow up top has been arround a while I think - I'm just now seeing it in my way.

 

[Justin DuBois]

For ECMLink, I have the MDP style Omni MAP sensor on 2g intake manifold MDP sensor port for now. For the boost controller, I am taking it from TB port. The port doesn't read vacuum when the throttle plate is closed, so it reads only boost, but I don't need my Profec boost controller to read vacuum so.

Your Omni4Bar and my GM3Bar are going to roughly the same place - directly into the intake manifold body. Mine is tapped on the back side of the 1G manifold, the Omni is on the top.

Side note - the Stack boost gauge is smoothing out the GM3Bar data, cause from the same sensor, the needle on the gauge is steady.

 

[ist dwa]

The slower the car and less boost the easier it is to line those up . You can spend the time tweaking the SD table also to dial in the A/F ratio, again close enough works, you are too focused on A/F ratio, it isn't that important. MAFs also count the air much better than SD giving a more accurate air to supply fuel for, it is an estimate vs actual counting.

Now I found this. I had a bunch of choppy stuff like you, after tuning I got it better but it was still choppy. The real culprit ended up being changing from an Omni bar 4 to a AEM silver 5 bar.

This is what boost readings were on a 4 bar

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